1. Field of the Invention
The present invention relates to a feeding apparatus that transfers a sheet-like medium to a carrying direction.
2. Description of the Related Art
There have been proposed various feeding apparatuses that transfer a sheet-like medium such as a paper sheet on a feed tray to a carrying direction. Japanese Patent Application Laid-open No. S50-87221 discloses one example of such a feeding apparatus.
In this type of feeding apparatus, a pickup roller makes contact with a medium on a feed tray and rotates, thereby transferring the medium in contacted therewith to a carrying direction from the feed tray. The medium transferred by the pickup roller makes contact with a separator roller, and is transferred to the carrying direction by a rotational force of the separator roller. A brake roller, for example, is arranged opposite the separator roller. If, for example, two sheet-like media enter between the separator roller and the brake roller, the brake roller makes contact with a separation target medium, i.e., a medium transferred by the pickup roller to the carrying direction together with a transfer target medium, and prevents the separation target medium from moving toward the carrying direction. The transfer target medium is a medium in contact with the separator roller. That is, the brake roller separates the separation target medium from the transfer target medium in contact with the separator roller. With this, each medium is transferred to the carrying direction one by one.
There are feeding apparatuses that switch a pickup roller between contact state and non-contact state with respect to a medium on a feed tray. The term “contact state” as used herein refers to state where the pickup roller can make contact with the medium on the feed tray, and the term “non-contact state” as used herein refers to state where the pickup roller is not in contact with the medium on the feed tray. In the feeding apparatus that switches the pickup roller between the contact state and the non-contact state with respect to the medium on the feed tray, when the pickup roller makes contact with the medium on the feed tray and rotates, the medium in contact with the pickup roller is transferred from the feed tray. An optical sensor provided near the separator roller then detects the leading edge of the medium. When the optical sensor provided near the separator roller detects the leading edge of the medium transferred by the pickup roller, the pickup roller is switched from the contact state to the non-contact state. That is, when the medium is transferred by the pickup roller from the feed tray to the separator roller, it is switched to the non-contact state. In other words, the pickup roller is in the non-contact state while the medium is being transferred by the separator roller. When the separator roller transfers the medium transferred by the pickup roller and, for example, when the trailing edge of the medium is detected by the optical sensor, the pickup roller is returned from the non-contact state to the contact state. That is, when the medium is transferred in the carrying direction by the separator roller, the pickup roller is switched to the contact state to transfer the next medium from the feed tray to the separator roller. In other words, in non-transfer state where the medium is not being transferred by the separator roller, the pickup roller is switched to the contact state. When the pickup roller makes contact with the medium on the feed tray and rotates again, the next medium in contact with the pickup roller is transferred from the feed tray.
As described above, a pick roller is brought in the state where it is not in contact with a medium on a feed tray, and a time period in which the pickup roller is in contact with the medium is suppressed to improve the durability of the pickup roller. However, sufficient durability of the pickup roller is not achieved by the conventional technologies, and there is a need for further improvement.